The name of the game is desired contact between a gas or vapor and a liquid. Basically, an arrangement is provided to release the vapor or gas beneath the surface of the treating liquid to ensure desired contact between the mediums.
A wide variety of shapes and arrangements have been developed for bubble caps in the prior art. All the configurations have at least one thing in common: they bring the vapor into intimate contact with the liquid on a tray. A plurality of trays, vertically stacked within a tower, establish a predetermined number of contacts between the vapor and the liquid. Each tray has an upstanding lip at its periphery below which the level of the treating liquid is held. The number of bubble caps needed to secure the desired contact between the vapor and liquid is calculated. Fundamentally, one or more riser tubes are mounted through the bottom of a tray, the treating liuqid is held on the tray at a predetermined depth, and the vapor to be treated is flowed up the riser tube and diverted downwardly by a telescoping cap which forces the vapor below the surface of the liquid on the tray where it is released to bubble up through the liquid. If the present support for the bubble cap at the top of the riser tube can be simplified, significant savings can be realized.
At present, the bubble caps are secured to the top of the riser tubes with a spider structure made up of several pieces welded to form a support for a central bolt. The cap is then captured on the upper end of this supported bolt to form an annular space between the inside of the cap and the outside of the riser tube. This spider of several pieces welded together is the structure which can be greatly simplified in pursuit of lower manufacturing costs.